急性未明系别白血病的诊断及鉴别诊断

Pathologic diagnosis and differential diagnosis of acute leukaemia of ambiguous lineage

目的探讨1例曾误诊为原始神经外胚层肿瘤(PNET)的急性未明系别白血病(ALAL)的组织病理学特点、诊断与鉴别诊断。方法对1例初诊为PNET的组织标本进行HE染色、常规Eli Vision免疫组化染色及原位杂交RT-PCR检测,最终明确诊断为ALAL后分析误诊原因并结合文献复习探讨其临床病理特点。结果女性,62岁,以右腮腺区肿物就诊。镜下为小圆或卵圆形肿瘤细胞排列成巢状或岛状,在腮腺中弥漫生长。免疫组化示瘤细胞vimentin、Td T和CD99(+),LCA、MPO、CD7、PAX5、CD68、CD163和CD15(-);RT-PCR检测示EWS-FLI-1及EWS-ERG融合基因(-)。结论 ALAL是一种罕见类型的血液肿瘤,由于罕见故治疗和预后未见报道。诊断依据临床和组织学特点,并结合免疫组化标记;鉴别诊断除与PNET鉴别外,还应与其他类型淋巴瘤及其他小圆细胞恶性肿瘤区别。

Objective To explore the histopathology,diagnosis and differential diagnosis of acute leukaemia of ambiguous lineage（ ALAL） that had been misdiagnosed as primitive neuroectodermal tumor（ PNET）. Methods Tissue samples were obtained from a patient who had been diagnosed as PNET. Histologic examination was performed on 4% buffered formalin fixed and hematoxylin-eosin（ HE）-stained sections with paraffin embedded samples. Immunohistochemical study was conducted with routinely Eli Vision method. RT-PCR was tested in University of Occupational and Environmental Health,Japan. Results A 62-year-old female patient presented with a mass of right submaxillary regin.Microscopically,morphology of the tumor cells was similar to blasts and diffused in parotid region. Immunohistochemical characterization of the tumors showed the expression of vimentin,Td T and CD99,whereas LCA,MPO,CD7,PAX5,CD68,CD163 and CD15 were negative. The specific chromosomal translocations of EWS-FLI-1 and EWS-ERG were negative. Conclusions ALAL is a rare hematopoietic neoplasm with uncertain therapy and outcome. The confirmed diagnosis is based on the aggregate analysis of its clinical characteristics,histological features,immunophenotype,and it should be distinguished from PNET and other sarcomas.